When new communication products promoted on the market, motto of Moore's Law: “double performance every 18 months” still under consideration by either customers or manufacturers. However, to meet those requirements, those communication products invoke better performance result in more power consumption and more heat generated and must be dissipated to ambient environment, otherwise the electronic component may slow down speedy performance.
Person skilled in the art have provided conventional heat dissipating device, as illustrated in FIG. 1, usually equipped with a fan rotated to circulate cooling air into fins to disperse heat absorbed by the fins.
The conventional heat dissipating device includes a housing (7) having a planar base (71), and a cover (72). A plurality of fins (8) are disposed on the base (71) inside the housing (7); a thermal conductor (81) disposed on the base (71) is further placed below the set of fins (8). Two heat pipes (80a, 80b) thermally connected to the thermal conductor (81) by bottom ends, but being inserted into the set of fins (8) by top ends. And, a fan (9) disposed inside the housing (7) is relative to the set of fins (8). As the conventional heat dissipating device is assembled integrally as whole, the communication product, for example, a graphic processing unit (GPU) of video graphic assays (VGA) card disposed adjacent to the housing (1). Heat generated by the communication product is transferred through the thermal conductor (81), the heat pipes (80a, 80b) to the set of fins (8). And the fan (9) circulates cooling air into the set of fins (8) to expel hot air out of an exhaust (10). Thus a temperature can be lowered to achieve a cooling effect. The communication product can be operated not to be overheated by the generated heat.
Furthermore, published US 20070211432 entitled “heat dissipating device for computer add-on card” to Xue-Wen Peng on Sep. 13, 2007 (hereinafter Peng) proposed that a heat pipe connected between a set of fins and a base. The heat pipe has an evaporating portion placed above a heat-generating GPU of VGA, and a condensing portion distant from the GPU of VGA but thermally connected to the set of fins.
As above, heat dissipating devices of FIG. 1 and Peng have some drawbacks as following:
1. The thermal conductor (81) of FIG. 1 dissipates heat via the two heat pipes (80a, 80b) to the set of fins (8), and then the fan (9) circulates cooling air into the fins (8) to disperse heat. Therefore, two heat pipes (80a, 80b) and the fins (8) lower temperature as the fan is rotated to circulate cool air into the fins. But Peng provided an evaporating portion (of a heat pipe), which is thermally connected to a heat-generating GPU of VGA, and a condensing portion (of the heat pipe) is kept distant from the GPU of VGA but thermally connected to the set of fins. Also the fan is rotated to circulate cooling air into the fins for dissipating heat.
As above, temperature may be lowered, but restricted to a limited scope, how to dissipate heat more efficiently for the communication products is expected by the invention.
2. To achieve a cooling effect, a fan must be rotated speedily, but more power consumed and more noise inducted. How to save power and reduce noise is further expected by the invention.
3. Either the two heat pipes of FIG. 1 or the heat pipe of Peng restricted to a limited cooling effect, which may not conform to new standards for the communication products. Therefore, the set of fins must be expanded with a larger surface or a huge body readily for dissipating heat. As a result, the enlarged heat dissipating device is incompatible with communication products.
How to provide a heat dissipating device can disperse more heat within a limited space is concerned by the invention.